The present invention relates generally to the field of emergency exit devices for doors, and the like.
It has heretofore been generally known to provide safety exit devices which are fabricated as complete units for attachment to one face of an emergency exit door, and wherein each unit comprises a swingable latch or reciprocable bolt as a component part adapted in the closed position of the door for latching or locking engagement with an appropriate strike or keeper mounted on the associated door frame.
Such prior structures have been generally known from a number of prior patents which are exemplified by the Deutscher, et al., U.S. Pat. No. 3,432,631, dated Mar. 11, 1969, which utilizes a reciprocable locking bolt; and the Williams, U.S. Pat. No. 3,877,262, dated Apr. 15, 1975, which utilizes a swingable latch locking member. The mechanisms disclosed in these patents utilize a push bar rather than a pivotally supported manually operable panic bar. In either case, a potentially dangerous and hazardous condition may arise in an emergency situation by reason of the placement of load friction forces on the latch or reciprocable bolt, either due to the operation of the pushbar or the pivotally supported panic bar, or as a result of people crowding against the exit door and pushing it in an opening direction prior to its being unlatched or unbolted. Such load friction forces may thus seriously affect and even prevent opening of the door.
The above noted friction load forces have been materially reduced in a more recently issued, commonly owned Brkic, U.S. Pat. No. 4,130,306, dated Dec. 19, 1978, in which multiple bolts are arranged to be actuated by the panic bar mechanism, and wherein the top of the door frame is provided with a fixed header bolt or strike that is arranged to move the diverging fingers of a rotatable latch structure into a latched position, when the door is closed, and into a non-latched position, when the door is opened. A dogging member is operable to dog the latch in its latching position, when the door is closed.
According to the present invention, it is proposed to provide an improved and simplified panic exit door mechanism of the rim type, which will eliminate the undesirable inherent friction load forces that are characteristic of those panic exit door actuating mechanisms having a conventional reciprocable bolt or pivotally swingable latch, and particularly in those embodiments where the bolt is mounted at the end of the panic exit door actuating mechanism and is positioned adjacent the swinging edge of the door. For such purpose, the present invention utilizes a rotatable bolt member having a star wheel configuration. This star wheel is positioned at one end of the panic exit mechanism, and arranged to be rotatably actuated by an associated strike mounted on the door frame to a bolted and to an unbolted position, respectively, by the closing and opening movements of the door. Arms of the star wheel are successively rotatable in one direction of rotation into salient bolted positions as determined by spring detent means, and operably associated latch means are arranged to normally permit rotation of the star wheel to bring the arms into their bolted positions, but normally oppose rotation of the star wheel in a reverse direction that would move the active bolt positioned arm from its bolted position to a non-bolted position, until the latch is released either by the actuation of a key-controlled cam or by means of the manual actuation of the push bar on the panic exit mechanism.